diff -r 29b0d0b61615 -r a6deb69743d4 src/hotspot/share/gc/shared/workgroup.cpp
--- a/src/hotspot/share/gc/shared/workgroup.cpp	Mon Nov 25 12:31:39 2019 +0100
+++ b/src/hotspot/share/gc/shared/workgroup.cpp	Mon Nov 25 12:32:07 2019 +0100
@@ -164,7 +164,7 @@
   void worker_done_with_task() {
     // Mark that the worker is done with the task.
     // The worker is not allowed to read the state variables after this line.
-    uint not_finished = Atomic::sub(1u, &_not_finished);
+    uint not_finished = Atomic::sub(&_not_finished, 1u);
 
     // The last worker signals to the coordinator that all work is completed.
     if (not_finished == 0) {